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A144270 Lower triangular array called S2hat(-1) related to partition number array A144269. +0
6
1, 1, 1, 3, 1, 1, 15, 4, 1, 1, 105, 18, 4, 1, 1, 945, 129, 19, 4, 1, 1, 10395, 1095, 132, 19, 4, 1, 1, 135135, 11880, 1119, 133, 19, 4, 1, 1, 2027025, 149940, 12057, 1122, 133, 19, 4, 1, 1, 34459425, 2218545, 151560, 12081, 1123, 133, 19, 4, 1, 1 (list; table; graph; listen)
OFFSET

1,4

COMMENT

If in the partition array M32hat(-1)=A144269 entries with the same parts number m are summed one obtains this triangle of numbers S2hat(-1). In the same way the Stirling2 triangle A008277 is obtained from the partition array M_3 = A036040.

The first three columns are A001147, A144272, A144273.

REFERENCES

W. Lang, Combinatorial Interpretation of Generalized Stirling Numbers, preprint Oct 2008.

LINKS

W. Lang, First 10 rows of the array and more.

FORMULA

a(n,m)=sum(product(|S2(-1;j,1)|^e(n,m,q,j),j=1..n),q=1..p(n,m)) if n>=m>=1, else 0. Here p(n,m)=A008284(n,m), the number of m parts partitions of n and e(n,m,q,j) is the exponent of j in the q-th m part partition of n. |S2(-1;j,1)|= A001497(j-1,0) = A001147(j-1) = (2*j-3)(!^2) (2-factorials) for j>=2 and 1 if j=1.

EXAMPLE

[1];[1,1];[3,1,1];[15,4,1,1];[105,18,4,1,1];...

CROSSREFS

Row sums A144271.

Sequence in context: A006956 A072285 A144269 this_sequence A110112 A156690 A060325

Adjacent sequences: A144267 A144268 A144269 this_sequence A144271 A144272 A144273

KEYWORD

nonn,easy,tabl

AUTHOR

Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de) Oct 09 2008

EXTENSIONS

First %C line: changed M32khat(-1) into M32hat(-1)=A144269.%e line: chabged [15,4,1] into [15,4,1,1]. - Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de), Oct 28 2008

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Last modified December 11 12:57 EST 2009. Contains 170656 sequences.


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